jd kit or pwk carb for 93 cr 250?

[01cr80]

this Christmas i want to get something for my bike because i cant get the jetting right, its either a pwk carb or the jd jetting kit. As you know my bike has the $hitty keihin pj carb but do think it will a lot better with just the kit? Or would the carb be that much better even thought its more than twice the price of the jetting kit?

[eyesky2002]

this Christmas i want to get something for my bike because i cant get the jetting right, its either a pwk carb or the jd jetting kit. As you know my bike has the $hitty keihin pj carb but do think it will a lot better with just the kit? Or would the carb be that much better even thought its more than twice the price of the jetting kit?

The PJ's issue is the choke/idle circuit, they get old and don't work right. A PWK has a separate idle screw that controls the slide height. JD kits are over rated IMHO. Also jetting changes with temp, you can run leaner in the heat, but it has to be set richer in the cold. So you may be able to run a 45-48 pilot in the summer, but you will have to run a 52-55 in the winter, same goes with a richer needle and the main. My CR500 for example runs a 45/172 1472 combo in the summer, but have to run 55/178 1368 in the winter (temps below 40f).

That said a JD kit is not a solve all.

I would get the new 39mm PWK, get it spec jetted 55/175 1370 needle and get a couple extra smaller pilot and main jets to tune it come warmer weather.

[CamP]

The PJ can be jetted to perfection. I wouldn't spend all that money on a carb conversion when you can make your PJ work well. A 1369 needle really cleans up the CR250 jetting. Costs about $12. You can also buy a new choke assembly for about $30 if yours is worn out.

[eyesky2002]

Tried that with my clean 94 PJ carb, still no smooth running or idle. New in the box PWK fired and idled first kick!

[01cr80]

Tried that with my clean 94 PJ carb, still no smooth running or idle. New in the box PWK fired and idled first kick!

im for sure getting the pwk, do you think it starts easier that before? does it foul plugs less? what other improvements did you see with the pwk?

[KcDavis]

My PJ works like a champ. Smooth idle and no jetting issues. But, it sounds like you have money burning a hole in your pocket, so I guess you might as well spend it.

[01cr80]

My PJ works like a champ. Smooth idle and no jetting issues. But, it sounds like you have money burning a hole in your pocket, so I guess you might as well spend it.

whats your jetting and elevation for the pj, if i can get it to work and i will keep the pj for sure, but after reading how much better the pwk than the pj it sounds like its worth it to get the pwk

[01cr80]

The PJ's issue is the choke/idle circuit, they get old and don't work right. A PWK has a separate idle screw that controls the slide height. JD kits are over rated IMHO. Also jetting changes with temp, you can run leaner in the heat, but it has to be set richer in the cold. So you may be able to run a 45-48 pilot in the summer, but you will have to run a 52-55 in the winter, same goes with a richer needle and the main. My CR500 for example runs a 45/172 1472 combo in the summer, but have to run 55/178 1368 in the winter (temps below 40f).

That said a JD kit is not a solve all.

I would get the new 39mm PWK, get it spec jetted 55/175 1370 needle and get a couple extra smaller pilot and main jets to tune it come warmer weather.

what bike did you swap the pj on? just the 500?

[CamP]

whats your jetting and elevation for the pj, if i can get it to work and i will keep the pj for sure, but after reading how much better the pwk than the pj it sounds like its worth it to get the pwk

Pro Circuit's recommended jetting is usually a good place to start up to about 1,500'.

For the 93 CR250:

172 main, 55 pilot, 1369 needle, 2ND clip, airscrew at 1 1/2 out.

[CamP]

whats your jetting and elevation for the pj, if i can get it to work and i will keep the pj for sure, but after reading how much better the pwk than the pj it sounds like its worth it to get the pwk

Pro Circuit's recommended jetting is usually a good place to start if you are between sea level and about 1,500'.

For the 93 CR250:

172 main, 55 pilot, 1369 needle, 2ND clip, airscrew at 1 1/2 out.

[01cr80]

right now i have the 1370 needle and the bike always fouls plugs and doesnt have much power, so wouldnt the 1396 needle make it even richer?

[CamP]

The 1369 is slightly richer near closed throttle. What is your current jetting, premix, ratio and plug? How do you use your bike? MX or off-road? When was top end rebuilt last? Does it have good compression? Is the power valve opperating properly? Lots of things can contribute to a lack of power, but if the engine is healthy, it should still scream on top, even if the jetting is too rich. If it's fouling plugs with proper jetting and the correct plug, the choke could be leaking, the inlet valve could be leaking and/or the floats set too high.

[01cr80]

The 1369 is slightly richer near closed throttle. What is your current jetting, premix, ratio and plug? How do you use your bike? MX or off-road? When was top end rebuilt last? Does it have good compression? Is the power valve opperating properly? Lots of things can contribute to a lack of power, but if the engine is healthy, it should still scream on top, even if the jetting is too rich. If it's fouling plugs with proper jetting and the correct plug, the choke could be leaking, the inlet valve could be leaking and/or the floats set too high.

Jetting- main-170 pilot-52 needle-1370 2nd position

premixed at 32:1

plug-br8eg

i ride mostly off road on trails and i pull the clutch in often and rev it to clear it out to try to avoid fouling plugs

complete engine rebuild with less than 4 hours on it with new piston, crank, bearings and seals, haven't tested compression but the cylinder was also replated and has new reeds

powervalve was cleaned 4 hours ago even though it didn't need it and i checked that it was working

i have checked the float level many times its at 16mm, we have another 1992 cr 250 parts bike so i have another carb, i set everything with the other carb a few days ago and rode it but it doesn't want to go into the powerband with that carb and sputters right before the powerband

[01cr80]

its bored to a 265 if that makes a difference also

[01cr80]

i tested the spark on the 1992 cr parts bike and it has spark, but when it sparks you dont have to push the kick starter very fast and it sparks a bunch of times, my 1993 only sparks once when i push the kick starter really fast. So obviously there was something wrong. I was going to switch each electrical component until i found the problem. So i started with the cdi since it was easy to switch, i got it on and the bike now sparks a like the 1992 parts bike did. It also doesn't take much force to get it to spark. I put the rest of the bike together and it started first kick!!! Thats a first, it almost even wants to idle! I shut off the bike and tried to start it again, it started in half a kick!!! Now it starts easy and seems to run good, but it was like 10 so i couldn't go ride it. Im so excited to go ride it tomorrow and see what it runs like.

[heart_of_darkness]

The PJ's issue is the choke/idle circuit, they get old and don't work right.

Is there a way to directly check whether a PJ choke tower is functioning correctly, other than just jetting issues?

[KcDavis]

Is there a way to directly check whether a PJ choke tower is functioning correctly, other than just jetting issues?

If you can pull the choke and it doesn't change how your bike runs, then something isn't working right.

[yota]

I've had PJ's work great and I've had them be a pain. usually it is the choke/idle assembly that is the problem, they are cheapest to purchase at Pats small Engine Parts (PSEP). usually when they mess up, when you pull it out it is broken in half.

I run the PWK's and they work well and are very consistant, if you have the money to burn.

Edited December 14, 2010 by yota

[01cr80]

so i was reading this thread about a guy with a 1996 cr 250 needing to replace his carb because it was worn out, i did not think whole carb bodies wore out. he said the slide was loose and wanted a new carb, he didnt seem like a complete idiot when it comes to bikes so idk, our 1971 z50 has the original carb and runs great.

[choppertown]

so i was reading this thread about a guy with a 1996 cr 250 needing to replace his carb because it was worn out, i did not think whole carb bodies wore out. he said the slide was loose and wanted a new carb, he didnt seem like a complete idiot when it comes to bikes so idk, our 1971 z50 has the original carb and runs great.

that would be me!!

there are a few things in the PJ carbs that cant be rebuilt, or i would just get all new parts for it and do so. i have also been dicking around with this PJ carb for a wile trying to get it right and it just dosent happen.

im only a 1/4 idiot.